EFFECT OF REGULATORY LIGANDS AND THEIR BINDING SITES ON PEP CARBOXYLASES

调节配体及其结合位点对 PEP 羧化酶的影响

• 批准号: 3856314
• 负责人: SCOTT D GROVER
• 金额: --
• 依托单位: CALIFORNIA STATE UNIVERSITY LOS ANGELES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3856314
• 关键词: Escherichia coli; chemical association; chemical binding; enzyme inhibitors; enzyme mechanism; enzyme structure; glucose 6 phosphate; ligands; phosphoenolpyruvate carboxylase

This research will explore the molecular interactions of phosphoenolpyruvate carboxylase with its regulatory ligands. Experimental emphasis will be focused on the enzyme from Crassula argentea, with comparative studies involving phosphoenolpyruvate carboxylase from E. coli and Z. mays. The metabolic inhibitor malate and the activator glucose 6-phosphate are the principal effectors to be studied. The specific aims include determining which ionization states are important for these effectors, the role of metal ions in effector binding, and what substructures of the effectors are essential for their regulatory activity. Interactions between malate and glucose 6-phosphate will be evaluated. Kinetic evidence of mutually exclusive binding of various inhibitors will be used to address the possibility of multiple inhibitor sites. Evidence will be obtained from chemical modification studies on the types of amino acid residues involved in effector binding, whether the effectors are binding at true allosteric sites, and how many distinct types of effector sites are present. Affinity labels will be developed which should prove to be useful probes of the regulatory sites of this enzymes, as well as bacterial and mammalian enzymes with binding sites for either of these two metabolic intermediates.

本研究将探讨分子间的相互作用